Validity and reliability of the Integrated Palliative care Outcome Scale (IPOS) for non-cancer patients

Abstract Purpose This study assessed the validity and reliability of the Integrated Palliative Care Outcome Scale (IPOS) for non-cancer patients. Methods We recruited 223 non-cancer patients receiving palliative care and their healthcare providers (222) across two home care facilities and two hospitals for a cross-sectional study. We assessed the construct validity and known-group validity of the IPOS for this cohort by dividing them into stable and non-stable groups based on disease status. The weighted kappa and interclass correlation coefficients were assessed to ascertain reliability. Results The IPOS scores were significantly higher for the ‘non-stable’ group (worsening condition group) measured in the palliative care phase than for the ‘stable’ group (p < 0.001). Concerning validity, Spearman’s correlations between similar IPOS and Edmonton Symptom Assessment System items ranged from 0.61 to 0.94. Regarding reliability, the weighted kappa coefficients ranged from 0.53 to 0.81 for patients and from 0.58 to 0.90 for healthcare providers. For inter-rater reliability between patients and healthcare providers, the weighted kappa coefficients for each item ranged from 0.05 to 0.42 for physical symptoms, 0.03–0.25 for emotional symptoms, and 0.05–0.15 for communication/practical issues. Conclusion This study confirmed the validity and reliability of IPOS for non-cancer patients requiring palliative care. However, the inter-rater reliability indicates poor agreement between patients and healthcare providers. This highlights the discrepancies between the patients’ and the healthcare providers’ assessments and the importance of the patient’s assessment.